MC68HC908GR4 MOTOROLA [Motorola, Inc], MC68HC908GR4 Datasheet - Page 163

• Manufacturer Part Number: MC68HC908GR4
• Description: Microcontrollers
• Manufacturer: MOTOROLA [Motorola, Inc]

11.8 FLASH Block Protection
MC68HC908GR8 — Rev 4.0
MOTOROLA
NOTE:
NOTE:
Programming and erasing of FLASH locations cannot be performed by
code being executed from the FLASH memory. While these operations
must be performed in the order shown, other unrelated operations may
occur between the steps. Do not exceed t
Characteristics.
Due to the ability of the on-board charge pump to erase and program the
FLASH memory in the target application, provision is made for protecting
a block of memory from unintentional erase or program operations due
to system malfunction. This protection is done by using of a FLASH
Block Protect Register (FLBPR). The FLBPR determines the range of
the FLASH memory which is to be protected. The range of the protected
area starts from a location defined by FLBPR and ends at the bottom of
the FLASH memory ($FFFF). When the memory is protected, the HVEN
bit cannot be set in either ERASE or PROGRAM operations.
In performing a program or erase operation, the FLASH block protect
register must be read after setting the PGM or ERASE bit and before
asserting the HVEN bit
When the FLBPR is programmed with all 0s, the entire memory is
protected from being programmed and erased. When all the bits are
erased (all 1s), the entire memory is accessible for program and erase.
When bits within the FLBPR are programmed, they lock a block of
memory with address ranges as shown in
Register. Once the FLBPR is programmed with a value other than $FF,
any erase or program of the FLBPR or the protected block of FLASH
memory is prohibited. The FLBPR itself can be erased or programmed
only with an external voltage, V
also allows entry from reset into the monitor mode.
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
Flash Memory
TST
, present on the IRQ pin. This voltage
PROG
FLASH Block Protect
maximum. See
FLASH Block Protection
Technical Data
Flash Memory
Memory
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